diff --git a/UMFPACK/Source/README.txt b/UMFPACK/Source/README.txt
new file mode 100644
index 000000000..8b8df99a1
--- /dev/null
+++ b/UMFPACK/Source/README.txt
@@ -0,0 +1 @@
+The amd_internal.h file must be an exact copy of AMD/Include/amd_internal.h.
diff --git a/UMFPACK/Source/amd_internal.h b/UMFPACK/Source/amd_internal.h
new file mode 100644
index 000000000..85d43930b
--- /dev/null
+++ b/UMFPACK/Source/amd_internal.h
@@ -0,0 +1,280 @@
+//------------------------------------------------------------------------------
+// AMD/Include/amd_internal.h: internal definitions for AMD
+//------------------------------------------------------------------------------
+
+// AMD, Copyright (c) 1996-2022, Timothy A. Davis, Patrick R. Amestoy, and
+// Iain S. Duff.  All Rights Reserved.
+// SPDX-License-Identifier: BSD-3-clause
+
+//------------------------------------------------------------------------------
+
+/* This file is for internal use in AMD itself, and does not normally need to
+ * be included in user code (it is included in UMFPACK, however).   All others
+ * should use amd.h instead.
+ */
+
+/* ========================================================================= */
+/* === NDEBUG ============================================================== */
+/* ========================================================================= */
+
+/*
+ * Turning on debugging takes some work (see below).   If you do not edit this
+ * file, then debugging is always turned off, regardless of whether or not
+ * -DNDEBUG is specified in your compiler options.
+ *
+ * If AMD is being compiled as a mexFunction, then MATLAB_MEX_FILE is defined,
+ * and mxAssert is used instead of assert.  If debugging is not enabled, no
+ * MATLAB include files or functions are used.  Thus, the AMD library libamd.a
+ * can be safely used in either a stand-alone C program or in another
+ * mexFunction, without any change.
+ */
+
+/*
+    AMD will be exceedingly slow when running in debug mode.  The next three
+    lines ensure that debugging is turned off.
+*/
+#ifndef NDEBUG
+#define NDEBUG
+#endif
+
+/*
+    To enable debugging, uncomment the following line:
+#undef NDEBUG
+*/
+
+#define SUITESPARSE_LIBRARY
+#include "amd.h"
+
+/* ------------------------------------------------------------------------- */
+/* basic definitions */
+/* ------------------------------------------------------------------------- */
+
+#ifdef FLIP
+#undef FLIP
+#endif
+
+#ifdef MAX
+#undef MAX
+#endif
+
+#ifdef MIN
+#undef MIN
+#endif
+
+#ifdef EMPTY
+#undef EMPTY
+#endif
+
+#define PRIVATE static
+
+/* FLIP is a "negation about -1", and is used to mark an integer i that is
+ * normally non-negative.  FLIP (EMPTY) is EMPTY.  FLIP of a number > EMPTY
+ * is negative, and FLIP of a number < EMTPY is positive.  FLIP (FLIP (i)) = i
+ * for all integers i.  UNFLIP (i) is >= EMPTY. */
+#define EMPTY (-1)
+#define FLIP(i) (-(i)-2)
+#define UNFLIP(i) ((i < EMPTY) ? FLIP (i) : (i))
+
+/* for integer MAX/MIN, or for doubles when we don't care how NaN's behave: */
+#define MAX(a,b) (((a) > (b)) ? (a) : (b))
+#define MIN(a,b) (((a) < (b)) ? (a) : (b))
+
+/* logical expression of p implies q: */
+#define IMPLIES(p,q) (!(p) || (q))
+
+/* Note that the IBM RS 6000 xlc predefines TRUE and FALSE in <types.h>. */
+/* The Compaq Alpha also predefines TRUE and FALSE. */
+#ifdef TRUE
+#undef TRUE
+#endif
+#ifdef FALSE
+#undef FALSE
+#endif
+
+#define TRUE (1)
+#define FALSE (0)
+#define EMPTY (-1)
+
+/* largest value of size_t */
+#ifndef SIZE_T_MAX
+#ifdef SIZE_MAX
+/* C99 only */
+#define SIZE_T_MAX SIZE_MAX
+#else
+#define SIZE_T_MAX ((size_t) (-1))
+#endif
+#endif
+
+/* ------------------------------------------------------------------------- */
+/* integer type for AMD: int32_t or int64_t */
+/* ------------------------------------------------------------------------- */
+
+#if defined (DLONG) || defined (ZLONG)
+
+#define Int int64_t
+#define UInt uint64_t
+#define ID  "%" PRId64
+#define Int_MAX INT64_MAX
+
+#define AMD_order amd_l_order
+#define AMD_defaults amd_l_defaults
+#define AMD_control amd_l_control
+#define AMD_info amd_l_info
+#define AMD_1 amd_l1
+#define AMD_2 amd_l2
+#define AMD_valid amd_l_valid
+#define AMD_aat amd_l_aat
+#define AMD_postorder amd_l_postorder
+#define AMD_post_tree amd_l_post_tree
+#define AMD_dump amd_l_dump
+#define AMD_debug amd_l_debug
+#define AMD_debug_init amd_l_debug_init
+#define AMD_preprocess amd_l_preprocess
+
+#else
+
+#define Int int32_t
+#define UInt uint32_t
+#define ID "%d"
+#define Int_MAX INT32_MAX
+
+#define AMD_order amd_order
+#define AMD_defaults amd_defaults
+#define AMD_control amd_control
+#define AMD_info amd_info
+#define AMD_1 amd_1
+#define AMD_2 amd_2
+#define AMD_valid amd_valid
+#define AMD_aat amd_aat
+#define AMD_postorder amd_postorder
+#define AMD_post_tree amd_post_tree
+#define AMD_dump amd_dump
+#define AMD_debug amd_debug
+#define AMD_debug_init amd_debug_init
+#define AMD_preprocess amd_preprocess
+
+#endif
+
+/* ------------------------------------------------------------------------- */
+/* AMD routine definitions (not user-callable) */
+/* ------------------------------------------------------------------------- */
+
+size_t AMD_aat
+(
+    Int n,
+    const Int Ap [ ],
+    const Int Ai [ ],
+    Int Len [ ],
+    Int Tp [ ],
+    double Info [ ]
+) ;
+
+void AMD_1
+(
+    Int n,
+    const Int Ap [ ],
+    const Int Ai [ ],
+    Int P [ ],
+    Int Pinv [ ],
+    Int Len [ ],
+    Int slen,
+    Int S [ ],
+    double Control [ ],
+    double Info [ ]
+) ;
+
+void AMD_postorder
+(
+    Int nn,
+    Int Parent [ ],
+    Int Npiv [ ],
+    Int Fsize [ ],
+    Int Order [ ],
+    Int Child [ ],
+    Int Sibling [ ],
+    Int Stack [ ]
+) ;
+
+Int AMD_post_tree
+(
+    Int root,
+    Int k,
+    Int Child [ ],
+    const Int Sibling [ ],
+    Int Order [ ],
+    Int Stack [ ]
+#ifndef NDEBUG
+    , Int nn
+#endif
+) ;
+
+void AMD_preprocess
+(
+    Int n,
+    const Int Ap [ ],
+    const Int Ai [ ],
+    Int Rp [ ],
+    Int Ri [ ],
+    Int W [ ],
+    Int Flag [ ]
+) ;
+
+/* ------------------------------------------------------------------------- */
+/* debugging definitions */
+/* ------------------------------------------------------------------------- */
+
+#ifndef NDEBUG
+
+/* from assert.h:  assert macro */
+#include <assert.h>
+
+extern Int AMD_debug ;
+
+void AMD_debug_init ( char *s ) ;
+
+void AMD_dump
+(
+    Int n,
+    Int Pe [ ],
+    Int Iw [ ],
+    Int Len [ ],
+    Int iwlen,
+    Int pfree,
+    Int Nv [ ],
+    Int Next [ ],
+    Int Last [ ],
+    Int Head [ ],
+    Int Elen [ ],
+    Int Degree [ ],
+    Int W [ ],
+    Int nel
+) ;
+
+#ifdef ASSERT
+#undef ASSERT
+#endif
+
+/* Use mxAssert if AMD is compiled into a mexFunction */
+#ifdef MATLAB_MEX_FILE
+#define ASSERT(expression) (mxAssert ((expression), ""))
+#else
+#define ASSERT(expression) (assert (expression))
+#endif
+
+#define AMD_DEBUG0(params) { SUITESPARSE_PRINTF (params) ; }
+#define AMD_DEBUG1(params) { if (AMD_debug >= 1) SUITESPARSE_PRINTF (params) ; }
+#define AMD_DEBUG2(params) { if (AMD_debug >= 2) SUITESPARSE_PRINTF (params) ; }
+#define AMD_DEBUG3(params) { if (AMD_debug >= 3) SUITESPARSE_PRINTF (params) ; }
+#define AMD_DEBUG4(params) { if (AMD_debug >= 4) SUITESPARSE_PRINTF (params) ; }
+
+#else
+
+/* no debugging */
+#define ASSERT(expression)
+#define AMD_DEBUG0(params)
+#define AMD_DEBUG1(params)
+#define AMD_DEBUG2(params)
+#define AMD_DEBUG3(params)
+#define AMD_DEBUG4(params)
+
+#endif